TPMS is the English acronym for Tire Pressure Monitoring System and it is a tire pressure and temperature monitoring system used to monitor the perspective blind area during driving. Although the concept of TPMS (Tire Pressure Monitoring System) is quite new in China, the TPMS regulations have been prepared and enforced in USA by federal legislation.
The existing tire pressure monitoring systems are mainly divided into two types:
One type is Pressure-Sensor Based (direct) Tire Pressure Monitoring System (PSBTPMS), which utilizes a pressure sensor installed on the tire to measure tire pressure and a temperature sensor installed on the tire to measure tire temperature, a radio transmitter to transmit the pressure information from inside the tire to the system on a central receiver module and then display the tire pressure data. When the tire shows any high pressure, low pressure or high temperature, the system will generate an alarm to warn the owner. It is of pre-event active defense type.
The other type is Wheel-Speed Based (indirect) Tire Pressure Monitoring System (WSBTPMS), which compares the speed difference of tires through the wheel speed sensor of the ABS (Anti-lock Braking System), so as to monitor the tire pressure. The ABS determines whether the wheel is locked through the wheel speed sensor, so as to decide whether to start the ABS. When the tire pressure is reduced, the weight of the vehicle will reduce the tire diameter, thus changing the speed of the vehicle. Such change of the vehicle speed will trigger the alarm system of the WSB to warn the owner to pay attention to the low tire pressure. Therefore, it is passive.
The statistics indicate that on the domestic expressways, the traffic accidents arising from tire blowout account for 70% of the total. In the USA, the proportion is as high as 80%. The reasons for tire blowout can be roughly classified as follows: (1) Too high tire temperature resulting in tire pressure rise. (2) A change of the atmospheric pressure resulting in too high tire pressure. (3) The tire leakage. Since the economic losses arising from tire blowout are huge, how to prevent tire blowout is an important subject in safe driving. It is also a prevent-oriented common subject.